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1、BRITISH STANDARD BS EN 60695-7-1: 1996 IEC 695-7-1: 1993 Fire hazard testing Part 7: Guidance on the minimization of toxic hazards due to fires involving electrotechnical products Section 1: General The European Standard EN 60695-7-1:1995 has the status of a British Standard ICS 13.220.40; 29.020 Li
2、censed Copy: sheffieldun sheffieldun, na, Thu Nov 09 01:40:16 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS EN 60695-7-1:1996 This British Standard, having been prepared under the direction of the Electrotechnical Sector Board, was published under the authority of the Standards Board and comes into
3、effect on 15 June 1996 BSI 10-1999 The following BSI references relate to the work on this standard: Committee reference GEL/89 Draft for comment 92/21670 DC ISBN 0 580 25637 5 Committees responsible for this British Standard The preparation of this British Standard was entrusted to Technical Commit
4、tee GEL/89, Fire hazard testing, upon which the following bodies were represented: Association of Manufacturers of Domestic Electrical Appliances British Cable Makers Confederation British Electrical Systems Association (BEAMA Ltd.) British Plastics Federation British Telecommunications plc Electric
5、al Installation Equipment Manufacturers Association (BEAMA Ltd.) Electricity Association Federation of the Electronics Industry Home Office Lighting Industry Federation Ltd. Ministry of Defence National Supervising Inspectorate Society of British Aerospace Companies Limited Warrington Fire Research
6、Centre Amendments issued since publication Amd. No.DateComments Licensed Copy: sheffieldun sheffieldun, na, Thu Nov 09 01:40:16 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS EN 60695-7-1:1996 BSI 10-1999i Contents Page Committees responsibleInside front cover National forewordii Foreword2 Text of EN
7、 60695-7-13 List of referencesInside back cover Licensed Copy: sheffieldun sheffieldun, na, Thu Nov 09 01:40:16 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS EN 60695-7-1:1996 ii BSI 10-1999 National foreword This British Standard has been prepared by Technical Committee GEL/89 and is the English la
8、nguage version of EN 60695-7-1:1995 Fire hazard testing Part 7: Guidance on the minimization of toxic hazards due to fires involving electrotechnical products Section 1: General published by the European Committee for Electrotechnical Standardization (CENELEC). It is identical with IEC 695-7-1:1993
9、published by the International Electrotechnical Commission (IEC). A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity
10、 from legal obligations. Cross-reference Publication referred toCorresponding British Standard EN 60695-4:1995 (IEC 695-4:1993) BS EN 60695 Fire hazard testing Part 4:1996 Terminology concerning fire tests Summary of pages This document comprises a front cover, an inside front cover, pages i and ii,
11、 the EN title page, pages 2 to 8, an inside back cover and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover. Licensed Copy: sheffieldun sheffieldun, na, Thu Nov 09 01:40
12、:16 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 60695-7-1 June 1995 ICS 13.220.40; 29.020 Descriptors: Fire hazard testing, minimization of toxic hazards, guidance, electrotechnical products English version Fire hazard testing Part 7: Guidance on t
13、he minimization of toxic hazards due to fires involving electrotechnical products Section 1: General (IEC 695-7-1:1993) Essais relatifs aux risques du feu Partie 7: Guide sur la minimalisation des risques toxiques dus des feux impliquant des produits lectrotechniques Section 1: Gnralits (CEI 695-7-1
14、:1993) Prfungen zur Beurteilung der Brandgefahr Teil 7: Anleitung zur Verringerung der toxischen Gefahr bei Brnden von elektrotechnischen Erzeugnissen Hauptabschnitt 1: Allgemeines (IEC 695-7-1:1993) This European Standard was approved by CENELEC on 1995-05-15. CENELEC members are bound to comply wi
15、th the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the Central Secretar
16、iat or to any CENELEC member. This European Standard exists in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a CENELEC member into its own language and notified to the Central Secretariat has the same status as the
17、official versions. CENELEC members are the national electrotechnical committees of Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom. CENELEC European Committee for Electrotec
18、hnical Standardization Comit Europen de Normalisation Electrotechnique Europisches Komitee fr Elektrotechnische Normung Central Secretariat: rue de Stassart 35, B-1050 Brussels 1995 Copyright reserved to CENELEC members Ref. No. EN 60695-7-1:1995 E Licensed Copy: sheffieldun sheffieldun, na, Thu Nov
19、 09 01:40:16 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EN 60695-7-1:1995 2 BSI 10-1999 Foreword The text of the International Standard IEC 695-7-1:1993, prepared by IEC TC 89, Fire hazard testing, was submitted to the formal vote and was approved by CENELEC as EN 60695-7-1 on 1995-05-15 without any
20、 modification. The following dates were fixed: Annexes designated “normative” are part of the body of the standard. Annexes designated “informative” are given for information only. In this standard, Annex ZA is normative and Annex A is informative. Annex ZA has been added by CENELEC. Contents Page F
21、oreword2 Introduction3 1Scope3 2Normative reference3 3Definitions3 4Principles of assessing toxic hazard in fires4 4.1General4 4.2Factors determining toxic hazard4 5Unusual specific toxicity and extreme toxic potency5 6Toxic hazard and hazard assessment5 Annex A (informative) Bibliography7 Annex ZA
22、(normative) Normative references to international publications with their corresponding European publications7 latest date by which the EN has to be implemented at national level by publication of an identical national standard or by endorsement(dop) 1996-07-01 latest date by which the national stan
23、dards conflicting with the EN have to be withdrawn(dow) 1996-07-01 Licensed Copy: sheffieldun sheffieldun, na, Thu Nov 09 01:40:16 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EN 60695-7-1:1995 BSI 10-19993 Introduction Electrotechnical products frequently become involved in fires. However, except for
24、 certain specific cases (e.g., power generating stations, mass transit tunnels, computer suites), electrotechnical products are not normally present in sufficient quantities to form the major source of toxic hazard. For example, in domestic dwellings and places of public assembly, electrotechnical p
25、roducts are usually a very minor source of fire effluent compared with, for example, furnishings. This section of IEC 695-7 endorses ISO/TR 9122-1:1989, Toxicity testing of fire effluents Part 1: General. The following is a summary of the views expressed in that technical report. “Small-scale toxic
26、potency tests as we know them today are inappropriate for regulatory purposes. They cannot provide rank orderings of materials with respect to their propensity to produce toxic atmospheres in fires. All currently available tests are limited because of their inability to replicate the dynamics of fir
27、e growth which determine the time/concentration profiles of the effluent in full-scale fires, and the response of electrotechnical products, not just materials. This is a crucial limitation because the toxic effects of combustion effluent are now known to depend much more on the rates and conditions
28、 of combustion than on the chemical constitution of the burning materials.” The evidence from real fires and fire casualties, when taken with data from experimental fire and combustion toxicity studies, suggests that chemical species of unusual specific toxicity are not important (see clause 5). Car
29、bon monoxide is by far the most significant agent contributing to toxic hazard. Other agents of major significance are hydrogen cyanide, carbon dioxide, heat (both radiative and convective), hypoxia (depleted oxygen), and irritants (references 1, 2 and 3). ISO/TR 9122-1 recognizes that effective mit
30、igation of toxic hazard is best accomplished by tests and regulations leading to improved resistance to ignition and limited rate of fire growth, thus limiting the level of exposure to fire atmospheres. The practical aim of this section is to provide a means to minimize the contribution of electrote
31、chnical products to toxic hazard in fires. 1 Scope This part of IEC 695-7 gives guidance on the application of the methodologies recommended by ISO TC92 SC3 for minimizing the toxic hazard from fires involving electrotechnical products, as expressed in the documents ISO TR 9122-1-6, Reference 7, in
32、Annex A, Bibliography. 2 Normative reference The following normative document, contains provisions, which, through reference in this text, constitute provisions of this section of IEC 695-7. At the time of publication, the edition indicated was valid. All normative documents are subject to revision,
33、 and parties to agreements based on this section of IEC 695-7 are encouraged to investigate the possibility of applying the most recent edition of the normative document indicated below. Members of IEC and ISO maintain registers of currently valid International Standards. IEC 695-4:1993, Fire hazard
34、 testing Part 4: Terminology concerning fire tests. 3 Definitions For the purposes of this section of IEC 695-7, the following definitions apply. Definitions are taken from IEC 695-4 or from its amendment 1. 3.1 combustion exothermic reaction of a substance with an oxidizer, with emission of effluen
35、t, generally accompanied by flames and/or glowing and/or emission of smoke 3.2 fire a process of combustion characterized by the emission of heat and effluent, accompanied by smoke and/or flame, and/or glowing 3.3 fire effluent the total gaseous, particulate or aerosol effluent from combustion or py
36、rolysis 3.4 ignition initiation of combustion 3.5 smoke a visible suspension of solid and/or liquid particles in gases resulting from combustion or pyrolysis Licensed Copy: sheffieldun sheffieldun, na, Thu Nov 09 01:40:16 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EN 60695-7-1:1995 4 BSI 10-1999 3.6
37、 fire scenario a detailed description of conditions, including environmental, of one or more of the stages from before ignition to the completion of combustion in an actual fire at a specific location, or in a full-scale simulation 3.7 toxicity the inherent properties of a substance to produce adver
38、se effects upon a living organism (e.g. irritation, narcosis, death, etc.) 3.8 narcosis the depression of the central nervous system causing reduced awareness and/or impaired physical capability, both of which lead to a reduced ability to escape. In severe cases, unconsciousness and finally death ma
39、y occur 3.9 pulmonary irritancy the action of toxicants on the lower respiratory tract which may result in breathing discomfort (e.g. dyspnoea, increase in respiratory rate). In severe cases pneumonitis or pulmonary oedema may occur some hours after exposure, which may be fatal 3.10 sensory irritanc
40、y the action of toxicants on the eyes and/or upper respiratory tract causing a painful sensation. This may be a direct stimulus of specialized receptors or as a result of tissue damage caused by the toxicants 3.11 toxic hazard the potential for injury or loss of life by exposure to toxicants with re
41、spect to their potency, quantity, rate of exposure, and concentration 3.12 toxic potency a measure of the amount of toxicant required to elicit a specific toxic effect. The smaller the amount required, the greater the potency 4 Principles of assessing toxic hazard in fires 4.1 General There is no si
42、ngle test to assess toxic hazard in fires realistically. Small-scale toxic potency tests are not capable on their own of assessing fire hazard. Current toxicity tests attempt to measure toxic potency of a laboratory generated fire effluent. Toxic potency should not be confused with toxic hazard. ISO
43、/TR 9122-1 states: “There is a need to attempt to integrate toxicity and combustibility information (and not to use toxicity information by itself as a basis for decisions on materials).” (3.3). “Ignitability and overall fire performance may be the prime considerations in reducing toxic hazard.” (8.
44、4). This section, therefore, reviews work in ISO and elsewhere which allows the assessment of individual contributions of the fire effluent to toxic hazard, and the possibilities for use of test results in hazard assessment. 4.2 Factors determining toxic hazard The main questions concerning reductio
45、n in toxic hazard from fire are: a) How much product is burned or pyrolyzed, and at what rate? (4.2.1) b) How toxic is the fire effluent? (4.2.2) c) How is escape impeded? (Time of exposure to toxic and thermal threats). (clause 6) By separating the problem into these major elements, it is possible
46、to start addressing it. 4.2.1 Burning rate To minimize toxic hazard, it is necessary to consider ignition and rates of fire growth and flame spread. The quantity of effluent generated is proportional to the quantity of product burned or pyrolyzed. The rate of effluent generation is determined by the
47、 rate of burning or pyrolysis. 4.2.2 Toxicity of fire effluent Fire effluent consists of a complex mixture of solid particulates, liquid aerosols, gases and vapours. Although fires may generate effluent of widely differing compositions, toxicity tests have shown that gases and vapours are a major fa
48、ctor causing acute toxic effects. The predominant effects may be separated into three classes: i) narcosis, ii) sensory and/or pulmonary irritation, and iii) those effects representing unusual specific toxicity or extreme toxic potency. The temperature and humidity of the inhaled atmosphere are also
49、 critical factors in threat to life, as is depletion of oxygen. Licensed Copy: sheffieldun sheffieldun, na, Thu Nov 09 01:40:16 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EN 60695-7-1:1995 BSI 10-19995 Work in ISO and elsewhere has shown: Most products and materials give fire atmospheres of generally similar toxic potency. No study has found evidence that substances of unusually high specific toxicity are important in real fires. Test data indicate that fire effluent from electrotechnical products offers no greater toxic potency than other materials